White matter microstructure in anorexia nervosa

Abstract

The neurobiological underpinnings of anorexia nervosa (AN) are unclear. White matter deficits have been described in the illness, but findings are inconsistent between studies. The aim of this study was to investigate differences in white matter microstructure in AN using diffusion-weighted imaging (DWI). It was hypothesised that people with AN, relative to a healthy control (HC) group, would show decreased functional anisotropy (FA) and increased mean diffusivity (MD) in the fornix and superior longitudinal fasciculus, consistent with previous literature. Analyses were conducted on 23 females with AN and 26 age- and gender-matched HCs using tract-based spatial statistics (TBSS). The results revealed widespread FA decreases and MD increases in the AN group. Our hypothesis was largely supported, although FA differences were not specifically found in the fornix. The findings suggest extensive differences in white matter structure in AN, which may contribute to AN pathophysiology.

Anorexia nervosa and diffusion weighted imaging: An open methodological question raised by a systematic review and a fractional anisotropy anatomical likelihood estimation meta‐analysis

“…Indeed, a recent study on the general population showed that malnutrition was mostly linked with a reduction in FA and with changes in neuropsychological results (Roy et al, 2015). Barona et al (2019) found an increased FA in different areas but this difference could be explained by the preliminary characteristic of meta-analysis studies of DWI in AN, as well as by the methodology applied: indeed, they included studies with acute patients without a full diagnosis of AN (Olivo et al, 2017) or without whole brain foci results (Cha et al, 2016), whereas our meta-analysis includes a higher number of studies (such as Phillipou, Carruthers, et al, 2018;Miles et al, 2018;and unpublished data;von Schwanenflug et al, 2019).…”

“…Five articles out of 18 reported an increased FA in AN patients compared to HC, with modifications in different brain areas (Cha et al, 2016;Frank, Shott, Hagman, & Yang, 2013;Hayes et al, 2015;Travis et al, 2015;Vogel et al, 2016). Fourteen studies out of 17 reported a reduced FA in AN patients (Cha et al, 2016;Frank et al, 2013;Frank, Shott, Riederer, & Pryor, 2016;Frieling et al, 2012;Gaudio et al, 2017;Hayes et al, 2015;Hu et al, 2017;Kaufmann et al, 2017;Kazlouski et al, 2011;Nagahara et al, 2014;Phillipou, Carruthers, et al, 2018;Travis et al, 2015;Via et al, 2014;von Schwanenflug et al, 2019). The area of reduced FA seems to spread to different brain areas.…”

“…Out of 24 studies derived from the systematic review, only the studies conducted among current AN patients were considered for the analysis. Only 10 articles reported a significant FA alteration in AN patients and were included in the ALE-analysis, in accordance with the ALEanalysis standards (Eickhoff et al, 2009;Frank et al, 2013;Frieling et al, 2012;Gaudio et al, 2017;Hu et al, 2017;Kazlouski et al, 2011;Nagahara et al, 2014;Phillipou, Carruthers, et al, 2018;von Schwanenflug et al, 2019;Via et al, 2014;Vogel et al, 2016). Five studies were excluded because they did not report whole brain cluster coordinates of increased or decreased FA (Cha et al, 2016;Frank et al, 2016;Miles et al, 2018;Pfuhl et al, 2016;Travis et al, 2015).…”

“…Our ALE-meta-analysis showed two different clusters of decreased FA in patients with AN, located in the left corona radiata and close to the left thalamus. The corona radiata is an important intersection of afferent and efferent pathways between the basal ganglia, the brainstem and the cortex, as depicted in Figure 3 (Frieling et al, 2012;Gaudio et al, 2017;Phillipou, Carruthers, et al, 2018;. Given the anatomical centrality of this area, its structural alterations may lead to functional repercussions on processes that are deemed to be involved in AN pathophysiology, such as emotion regulation and taste/smell (Frank, 2015;Karababa, Bayazıt, Kılıçaslan, & Celik, 2015).…”

White Matter Abnormalities in Anorexia Nervosa: Psychoradiologic Evidence From Meta-Analysis of Diffusion Tensor Imaging Studies Using Tract Based Spatial Statistics

“…Unfortunately, their results are not consistent. Most studies report lower FA in widespread WM regions, including the corpus callosum (CC) (Frieling et al, 2012;Frank et al, 2013;Shott et al, 2016;Gaudio et al, 2017;Phillipou et al, 2018;von Schwanenflug et al, 2019), fornix fibers (Kazlouski et al, 2011;Frank et al, 2013;Gaudio et al, 2017), thalamus (Frieling et al, 2012;Hu et al, 2017), cingulum (Kazlouski et al, 2011;Frank et al, 2013), posterior thalamic radiation (PTR) (Phillipou et al, 2018), superior longitudinal fasciculus (SLF) (Via et al, 2014), fronto-occipital fasciculus (FOF) (Kazlouski et al, 2011;Via et al, 2014), corona radiation (Shott et al, 2016;Phillipou et al, 2018) and cerebellum (Nagahara et al, 2014;Shott et al, 2016). Five studies, however, observed no significant FA differences between AN patients and HC (Yau et al, 2013;Cha et al, 2016;Pfuhl et al, 2016;Bang et al, 2018;Olivo and Swenne, 2019).…”